I am a painter. I took a photo of a painting and noticed that the aspect ratio looked a little off.

[jwt99]

The aspect ratio looked slightly wider in the horizontal and shorter in the vertical aspect.  I turned the painting horizontal and took a photo and it looked correct but when I rotated it to upright in digital photo pro it returned to the slightly wider and shorter than reality aspect ratio.  Any help would be appreciated. I am using a EOS 40D camera.

[ebiggs1]

" I am using a EOS 40D camera."

If I am understanding you correctly and there is a high probability I am not, there is something wrong with the camera,  It is not firmware.  It has to be a malfunction in the camera itself.

A photo taken and properly cropped to size from the same camera has to look the same.  No matter what size the original is.

BTW, I don't think Canon still works on the 40D so that may not be an option.

[jwt99]

I spoke to Canon support tech today and he said it is probably a bad image sensor.  He also said they are still working on the 40D but if it is the sensor it might be expensive to repair. In pixels  if everything was perfect at 300 pixels/inch I should (for a 20X16 image) have pixel readings roughly6000X4800 or simplified 3000X2400 but I took a photo last night of a 20X16 painting and it read approximately 3888X2592 and that causes it to look a little shorter and wider than the original looks.  16X20 should have a ratio opf 1:1.25 and a 16x 24 painting should have an image ratio of 1:1.5. I took a photo of a 24X16 painting and it should read3600X2400 but it also read 3888X2592 and that causes it to look a lot shorter and wider than the original. Notice that I am getting the same readings for height and width in pixels for 16X20 and for 16 X 24 inch painting images.   I turned the paintings on their sides and got the expected pixels of 3600X2400 but when I rotated it to upright it changed to( you guessed it) 3888X2592.  So something is clearly not functioning properly. But, interestingly, when I turned it on and off a few times and tried again I got a nearly perfect JPEG  twice and numbers not as far off as before but when I reviewed several images they were mostly off by the amount shown above.  It seems the sensor is varied in amount of error and occasionally it is working properly, but most images are not correct and the more the aspect ratio varies from 4:5 (16X20) the more error is introduced.  I got several that showed the same pixels for the 4:6 ratio(16X24) as for the 4:5  3888X2592.

[Waddizzle]

"I took a photo of a 24X16 painting and it should read3600X2400 but it also read 3888X2592 and that causes it to look a lot shorter and wider than the original." 

Why should taking a picture of a 24x16 painting produce an image that is 3600x2400?  What does one have to do with the other?  The camera could care less what image is beng captured.  It will, or at least should, produce an image at a given resolution.

Maybe I am not fully understanding your issue, either.  Are you saying that you can take photos at a specific resolution, but  that the resulting files can vary in size?

"I turned the paintings on their sides and got the expected pixels of 3600X2400 but when I rotated it to upright it changed to( you guessed it) 3888X2592." 

No, I didn't guess it, or even get it.  How are you rotating the images?  In the camera?  In post processing?

[TTMartin]

"I turned the paintings on their sides and got the expected pixels of 3600X2400 but when I rotated it to upright it changed to( you guessed it) 3888X2592." 

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3600X2400 and 3888X2592 are the same aspect ratio.

 3600 / 2400 = 1.5

3888 / 2592 = 1.5

Same aspect ratio!

[RobertTheFat]

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@TTMartin wrote:

"I turned the paintings on their sides and got the expected pixels of 3600X2400 but when I rotated it to upright it changed to( you guessed it) 3888X2592."  

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3600X2400 and 3888X2592 are the same aspect ratio.

 3600 / 2400 = 1.5

3888 / 2592 = 1.5

Same aspect ratio!

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The aspect ratio is the same, but the resolution isn't. I wonder if the problem (if any) is that the OP is inadvertently using different magnification settings in the two cases.

[TTMartin]

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@RobertTheFat wrote:

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@TTMartin wrote:

"I turned the paintings on their sides and got the expected pixels of 3600X2400 but when I rotated it to upright it changed to( you guessed it) 3888X2592."  

---

3600X2400 and 3888X2592 are the same aspect ratio.

 3600 / 2400 = 1.5

3888 / 2592 = 1.5

Same aspect ratio!

---

The aspect ratio is the same, but the resolution isn't. I wonder if the problem (if any) is that the OP is inadvertently using different magnification settings in the two cases.

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3888 X 2592 is the 40D's full resolution. 

I suspect this is a computer software / user issue, and not a camera issue.

[RobertTheFat]

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@TTMartin wrote:

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@RobertTheFat wrote:

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@TTMartin wrote:

"I turned the paintings on their sides and got the expected pixels of 3600X2400 but when I rotated it to upright it changed to( you guessed it) 3888X2592."  

---

3600X2400 and 3888X2592 are the same aspect ratio.

 3600 / 2400 = 1.5

3888 / 2592 = 1.5

Same aspect ratio!

---

The aspect ratio is the same, but the resolution isn't. I wonder if the problem (if any) is that the OP is inadvertently using different magnification settings in the two cases.

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3888 X 2592 is the 40D's full resolution. 

I suspect this is a computer software / user issue, and not a camera issue.

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But 3600 X 2400 isn't. Which suggests that the user is seeing a slightly magnified image in that case. Whether the magnification is due to software (a photo editor) or hardware (a setting on the camera with which he's viewing it) is an implementation detail.

[jwt99]

I used the rotation feature in digital image pro.  It was giving me the same aspect ratio as it was giving for the 20X16 paiting when I took a photo of a 24X16 painting.  It did the same thing at least a dozen times.  But when I turned off the camera and waited awhile to take another set of photos of 20X16 and 24X16 paintings it took much closer to correct photos.  So it seems that the camera isn't working properly.  I will send it to Virginia and see what they say.

[jwt99]

300pixels/inch x20 =6000 300X24=7200 16 x 300 =4800  simplified in the file properties 3000 0r 3600 or 2400

[jwt99]

That is interesting.  I don't know what is causing the issue then.  Clearly I am not grasping the problem but the camera is making photos of 16X20 and 16X24 paintings have the same aspect ratio when obviously they shouldn't be the same.  The original looks like a 16x24 painting which should yield a 4800 X 7200 pixel image but instead is giving me the same pixels that it gave for a 16 X20 painting 2592 X 3888.  It looks much shorter and wider than the original.  I would love for it to be my issue.  Explain how that is a user problem and what I need to do to fix it please? 16x20 should be something close to 4800 X 6000 @ 300/inch.  16x 24 should be close to 4800 x 7200 pixels @300pixels/inch.